Telephonic apparatus.



4 H. E. SHRBEVB.

TBLB'PHONIC APPARATUS. APPLICATION FILED JAN. 14, 1913- y WM AW- Patented Mar. 2, 1915.

UNITED STATES PATENT OFFICE.

HERBERT E. SHREEVE, OF MILBURN, NEW JERSEY, ASSIGNOR TO WESTERN ELECTRIC COMPANY, OF NEW YORK, N. Y., A CORPORATION OF ILLINOIS.

TELEPHONIC APPARATUS.

Application filed January 14, 1913.

To all whom it may concern Be it known that I, HERBERT E. SHREEVE, a subject of the King of Great Britain, residing at Milburn, in the county of Essex and State of New Jersey, have invented a certain new and useful- Improvement in Telephonic Apparatus, of which the following is a full, clear, concise, and exact description.

This invention relates to telephonic apparatusand more particularly to' a. telephonic transmitting device.

The objects of this inventionare to provide a new and improved telephone trans mitter that will efficiently operate with the maximum range ofsounds, will be free from the packing of the granulated resistance varying medium so detrimental in most forms of telephone transniiitters, that will be of few and simple parts and one that will maintain its adjustment under varying and trying conditions.

Atransmitter made in accordance with this invention comprises generally a base within which is a horizontally arranged granule containing chamber within which chamber is located .a vertically movable electrode operatively connected with a diaphragm responsive to sound waves, said electrode being mounted to dip into comminuted conducting material in the granule containing chamber. The diaphragm may mounted in any desired position so long as the chamber containing the resistance varying medium is maintained in a substantially horizontal position.

In the drawings illustrating this inve n tion,-Figure 1 is a vertical sectional iew of a transmitter embodying this invention, and Fig. 2 is a plan view of the transmitter with a part broken away.

Referring to the drawings 5 designates a main body portion of comparatively thick metal which will form a. heat radiating element. This body portion is provided at its top with a screw threaded portion 6 adapted to receive a cap 7 and is provided on its lower portion with a recess 8. The said body portion is hollowed out to form a chamber, the upper portion of which is comcal in shape, as shown at 10, the larger end opening adjacent to the upper margin of the said body portion and the smaller end opening into a cylindrical portion 11 of said chamber. The cylindrical portion 11 of the Specification of Letters Patent.

Patented Mar. 2, 1915.

Serial No. 741,930.

chamber is lined with an insulating lining 12 and contains comminuted conductin r b material 13. Located in the bottom of this cylindrical portion 11 of the chamber is a stationary electrode 15 connected with a metal screw threaded studs 16 which extends through an opening 17 in the bottom of the body portion 5 and is provided with a clampmg nut 18 for securing it in place and a terminal connecting nut 19.

Mounted upon the upper margin of the body portion 5 is a diaphragm 25 which is clamped thereon by means of the cap 7'. Secured to the central portion of the diaphragm 25 is a downwardly ext-ending stud 26 to the lower end of which is attached an electrode 27 having sloping side faces which may be either convergent or divergent at the lower end. The electrode shown is conical in shape and is arranged With its end of larger diameter to dip into the comminuted conducting material 13 in the manner of a liquid transmitter. The electrode 27 is provided with an upturned edge 30, the purpose of which is to expose more surface of the electrode to the resistance varying medium. An electrode of this shape, while exposing sufficient surface to the resistance varying medium to adequately conduct all of the current which is required, will by its movement keep the whole body of comminuted material insuch a state of agita' tion as to prevent its packing, and will also confine the current flow to the portion of the cornminuted material which is subject ed to the greatest amount of agitation.

The cap 7' which is provided with a plurality of openings 35, for the passage of the sound waves is parabolic so that all sound waves passing through the openings in said cap will be deflected or concentrated upon the diaphragm.

The electrode 27 is electrically connected with the dia 'ihragn'i 25 which is in electrical connection with .the body portion 5. The current conductors are connected, one with a binding screw 36 secured in said body portion, the other terminal being connected with the stud 16 connected with the stationary electrode.

As will be readily apparent from the, de scription and the drawings, the device is one that may be easilv and economically manufactured, one that is compact with all of the parts secured in a relation not easily disturbed by jar incident to rough handling and usage, and one that is efiicient in its op eration.

Any of the comminuted material which is displaced from the portion 11 of the chamber due to the tipping of the device will by virtue of the sloping Wall 10 be returned to the portion 11 when the device is again placed in position for use.

I clain1- 1. In a telephone transmitter, comminuted conducting material and relatively movable electrodes, one of said electrodes being flat and supporting said comminuted conducting material and the other of said electrodes having sloping faces and being only partially in contact with said comminutedconducting material whereby the surface area of contact between said sloping-faced elec trode and said comminuted conducting material is varied by the relative movement of said electrodes.

2. In a telephone transmitter, a main body portion having a chamber formed therein, comminuted conducting material in said chamber, electrodes in said chamber having a vertical movement relative to each other, one of said electrodes supporting said comminuted conducting material, the other being conical in form and having an upturned edge which dips into said comminuted conducting material.

3. In a telephone transmitter, a body portion having a chamber formed therein, comminuted conducting material in said chamber, movable and stationary electrodes in operative relation to said coinlninuted conducting material, a diaphragm operatively chamber, movable and stationary connected with said movable electrode, t a parabolic sound concentrating devise in operative relation to said ed to receive and concentra phragzn, sound Waves from directions.

1. In a telephone transinitte portion having a chamber 1 v comininntefi ,zonducting install ctrodes operative relation to said. comminuted conducting material, a diaphragm operatively connected with. said movable electrode and a parabolic cap having openings therein, said cap having screw three l e ment with said body portion for clamp-n said diaphragm to said body portion. 5. In. a telephone transmitter a bod y tion having a chamber formed therein, chamber having a lower cylindrical por tion and an upper conical portiointhe larger end opening adjacent the upper margin of said body portion, and the l wer end opening into said cylindrical portio min'uted conducting material in. said U in drical portion slumber, movable and strati ied; we rodes in operative rela tion to said cor rninuted conducting mate rial, and a diaphragm secured to the upper margin of said body portion and closing said chamber.

In Witness whereof, I hereunto subscribe,

my name this 11th day of January'A. 1).,

1913. HERBERT E. SHREEVE. Witnesses WALTER F. HoFFMAN, O, D. ML {iL-THE.

I I Sam 

